Rapid methodology for design and performance prediction of integrated supersonic combustion ramjet engine

Abstract

The design integration of a supersonic combustion ramjet engine (SCRAMJET) with an airframe dictates the mission success of transatmospheric or hypersonic cruise vehicles. Special interest must be given for the hypersonic atmospheric boost phase of the mission where most of the propulsive energy is expended. For this purpose, the operational efficiency is established by the effective specific impulse and the thrust to weight ratio of the accelerating vehicle. In order to analyze the foregoing problems, a methodology is developed, which permits a quick performance evaluation of an idealized, integrated SCRAMJET vehicle for preliminary design analysis. The capabilities of methodology are 1) designing an integrated vehicle consisting of the forebody inlet, supersonic flow combustor and afterbody expansion nozzle; 2) generating the design and off-design performance data; and 3) performing many design iterations for tradeoff studies. Samples of the design and off-design performance analysis of generic hypersonic vehicles are presented. The methodology is suitable to be programmed and executed on a personal computer.